“A recent survey showed that more than 40% of farmers still select varieties based on experience, sticking with what they have grown before” comments Tim Richmond, Maize Manager with Limagrain UK. “This means they are missing out on the huge advances that have been made in plant breeding, particularly in terms of the feed quality produced.”
“In the last 24 years, the milk production potential of maize varieties has increased from 30,900 litres/ha to 44,800 litres. That is an increase of 45% and demonstrates why farmers need to commit to new varieties rather than sticking with varieties that might have been successful in the past. We have seen advances in yield, feed quality and agronomy, which combined mean new varieties can give a better return on investment.”
He maintains that maturity class must still be the primary selection criterion but says that once a shortlist of varieties has been developed that meet the agronomic demands of the farm site, it is then vital to select varieties deliver the highest quality forage to ensure maize supplies the maximum benefit in terms of reducing feed costs and improving margins. He says clear breeding objectives have helped deliver varieties better suited to UK conditions, in particular with earlier harvesting.
“Early varieties were unpopular initially as they tended to come with a dry matter yield penalty. You got the crop off earlier but there was less of it in the clamp. This penalty has now gone and the new early varieties also have excellent starch and total energy content. Much of the UK is classified as less favoured sites for growing maize, which means it can be a struggle getting later varieties to maturity or, as recent years have demonstrated, harvested at all.
“An early variety can be harvested in good time, usually in better conditions and because the leaf and stover are harvested greener, the crop will have higher digestibility and consolidate better in the clamp. They also have the distinct advantage that being harvested sooner it will be easier to establish a successor crop, improving total production per acre and reducing soil erosion risks.
When looking at production characteristics, Mr Richmond explains that it is important to look at total energy yield rather than just starch content, commenting that up to 50% of the total energy available is in the leaf, stover and other vegetative material. He says that the Limagrain breeding programme is the only commercial programme which places particular emphasis on cell wall digestibility.
“The cob is 92-100% digestible so there is little opportunity to influence energy yield. However, the rest of the plant is 40-70% digestible, meaning if cell wall digestibility (CWD) can be improved so the energy available will increase. The only way to significantly increase energy production per hectare is by improving CWD, and improving CWD improves more than just energy content and yield.”
He says research by Professor Mike Wilkinson from the MGA shows that each 1% increase in fibre digestibility will increase dry matter intakes by 0.12kg/day, giving another benefit from selecting varieties with higher cell wall digestibility. This compares well with American research which showed each 1% rise in CWD increased total dry matter intake by 0.17kg/day resulting in a yield increase of 0.25 litres per cow per day.”
By selecting varieties with a good balance of starch and CWD, he says farmers will optimise production from forage and reduce purchased feed requirements.
“Farmers should look closely at starch content, CWD and energy yield when refining their initial variety shortlist, as there is a significant difference in milk yield per hectare between average and top varieties ranked on energy yield.”
Mr Richmond explains that Limagrain has identified varieties which have the genetic potential to deliver superior nutritional value. “Our Limagrain Animal Nutrition (LGAN) varieties are evaluated for all the key parameters affecting nutritional value, namely starch content and yield, ME content, and yield, CWD, dry matter yield, dry matter percent at harvest and early vigour. We combine five years of BSPB/NIAB data with five years of our own data to ensure only robust information is used.
“Currently there are seven LGAN accredited varieties on the descriptive lists. Some are well established such as Glory and Ambition while others such as Reason are new to the list.
“A high quality variety, Glory will supply sufficient energy to produce an extra 630 litres per hectare compared to the average variety. This equates to a concentrate feed saving of around £65/ha. For a farm growing 30ha of maize, selecting Glory over the average variety would cut the purchased feed bill by £1950 with no increase in growing costs compared to an average variety. With feed costs on the rise, this financial benefit of selecting varieties shown to support higher milk production will only increase.”
One farming family who has made the switch from selecting varieties based on dry matter yield to selecting on the basis of feed quality and early maturity is the Wainwright family from Ellesmere in Shropshire.
Phillip Wainwright farms in partnership with his two brothers David and Stephen and his two sons George and Charles, running a herd of 200 all year round calving cows averaging 9000 litres. High yielders are housed all year with access to a loafing area while low yields will usually graze from mid-April to mid-October.
Until eight years ago the herd was housed on two farm near Macclesfield, one owned and one rented, where they used to run a retail milk round. They decided to move out of retailing and to focus on the cows so they sold the farm they owned, took on the farm at Ellesmere and doubled the herd size while retaining the rented farm which is now used for heifer rearing.
“When we took over the farm there was a standing crop of maize and this was our first experience with the crop,” explains George Wainwright. We were really pleased how it fed and have been growing it ever since.
“The forage in the TMR is typically two thirds grass and one third maize, but we can’t feed maize all year round as we don’t have the clamp capacity and layout to allow us to do this. For the short period when we are out of maize we feed wholecrop but never get as much milk.”
For the first four years the Wainwrights tended to grow later maturing, high yielding varieties but since 2014 they have been working with Mark Hancock from Spunhill Farm Sales and have changed their selection criteria
“As the farm isn’t all suitable for maize and because they want to get maize in the diet as quickly as possible, I advised George and Philip to move to early maturing varieties,” Mark Hancock explains. “At the same time we looked to move to higher feed value varieties to improve forage quality and production from home grown feeds.
“They had been growing several varieties each year but now grow just the one which has benefits at harvest as the crop all matures at the same time. We first moved to the Limagrain variety Yukon but for the last two years have grown Glory very successfully.”
In 2016 they grew 54 acres of Glory which was drilled on the 1st may, as soon as soil temperatures were suitable. The crop was harvested on 16th October, yielding 16 tonnes per acre.
“To help get the maize off to a good start it was drilled with 8kg of a micro-granular 12:52:00 placement fertiliser, followed by 50kg N/Ha and 100kg/Ha of Potash,” Mark Hancock continues. “All fields also received an application of slurry.”
For weed control all fields had a pre-emergence herbicide, with post-emergence sprays used on specific fields as required.
“This year the weather were ideal and the crop came off early in excellent condition and has analysed really well, giving us a high quality feed. Last year, as we had made wet grass silage we harvested the maize later so we had a drier feed to balance out the grass. It still analysed and fed well.
“Early varieties certainly suit the farm and allow us to grow maize on more fields. This combined with the higher feed value means we can produce more from forage and we would look to feed maize all year round if we could,” George concludes.
The Wainwrights 2016 Glory analysis –
|Dry matter (%)||39.7|
|D value (%)||72|
|Crude protein (%)||8.2|